Method for increasing the effective thickness and resiliency of sheet metal and sheets produced thereby



J. H. VICTOR 2,969,586 METHOD FOR INCREASING THE EFFECTIVE THICKNESS AND RESILIENCY OF SHEET METAL AND SHEETS PRODUCED THEREBY I Jan. 31, 1961 3 sheets sheet 1 Filed April 24, 1957 Johfz i Vwim' Jan. 31, 1961 J. H. VICTOR METHOD FOR INCREASING THE EFFECT 2,969,586 7 IVE THICKNESS AND RESILIENCY 0F SHEET METAL AND SHEETS PRODUCED THEREIBY 3 Sheets-Sheet 2 I Filed April 24, 1957 Jan- 31, 1961 J. H. VICTOR 2,969,586

METHOD FOR INCREASING THE EFFECTIVE THICKNESS AND RESILIENCY OF SHEET METAL AND SHEETS PRODUCED THEREBY 3 Sheets-Sheet 3 Filed April 24, 1957 METHOD FOR INCREASING THE EFFECTIVE THICKNESS AND RESILIENCY F SHEET METAL AND SHEETS PRODUCED THEREBY John H. Victor, Wilmette, Ill., assignor to Victor Manufacturing & Gasket Co., Chicago, 111., a corporation of Illinois Filed Apr. 24, 1957, Ser. No. 654,777

'5 Claims. (Cl. 29-1835) copper, so as to increase its effective thickness by forming in it a plurality of closely spaced hollow projections rising out of both its obverse and reverse faces.

Another object of the invention is to provide a method of treating sheet metal so as to increase its resiliency under pressures applied at right angles to the faces of the sheet.

Another object of the invention is to provide a method of treating sheet metal so as to enhance securing coating materials to the faces of the sheet.

I Another object of the invention is to provide a sheet of metal formed to greater effective thickness and to greater resiliency than that of the stock from which the sheet is made.

Another object of the invention is to provide a sheet of metal the faces of which have been treated by formirlllg to enhance the securing of surface coatings to the s eet.

Further objects of the invention not specifically mentioned here will be apparent from the detailed description and claims which follow, reference being had to the accompanying drawings in which a preferred embodimcnt of the invention is shown by way of example and in which:

Fig. 1 is a photographic view of the obverse face of a sheet of metal treated in accordance with the teachings of the present invention and magnified approximately 20 diameters;

Fig. 2 is a view similar to Fig. 1, showing the reverse face of the sheet;

Fig. 3 is a photographic edge view of the sheet shown in Figs. 1 and 2, magnified to approximately 60 diameters;

Fig. 4 is a diagrammatic side view at an enlarged scale, of the dies with which the sheet shown in Figs. 1, 2 and 3 may be made;

Fig. 5 is an end view of the dies shown in Fig, 4;

Fig. 6 is a plan view of a section of the dies shown in Figs. 4 and 5;

Fig. 7 is a photographic view of the obverse face of a sheet of metal of another embodiment of the invention magnified approximately 20 diameters;

Fig. 8 is a photographic edge view of the sheet shown in Figs. 7 and 9, magnified to approximately 60 diameters;

Fig. 9 is a view similar to Fig; 7, showing the reverse face of the sheet.

Fig. 10 is a diagrammatic side view at an enlarged scale, of dies with which the sheet shown in Figs. 7, 8 and 9 may be made;

United States Patent 0 Fig. 11 is an end view of the dies shown in Fig. 10; and

Fig. 12 is a plan view of a section of the dies shown in Figs. 10 and 11,

Sheet metal, such as steel, brass or copper, available upon the open market, is formed by rolling under high pressure, and therefore requires very high pressures to further compress it in a direction at right angles to the faces of the sheet. Furthermore, such metal has little or no recovery, and upon removal of the pressure compressing it, the metal remains set in or near the position into which it was forced by that pressure.

Thus, for example, a sheet of metal of the order of .036 of an inch thickness, when subjected to pressures in the range of 5,000 pounds per square inch, will be compressed so little as to be virtually unmeasurable by ordinary means, and upon removal of the pressure the sheet shows no measurable recovery. The same condition prevails if sheets of lighter gauge metal are stacked together to produce a desired thickness.

In the prior art of which I am aware, the resiliency of an all metal cylinder head gasket has been increased by forming, in relatively thin metal, beads which increase the effective thickness of the sheet. Such gaskets when clamped between engine parts seal only at the beads. Also in the prior art of which I am aware, prongs have been struck out of a sheet metal and embedded in sheets of a compressible material, such as asbestos, to form gaskets in which the compressibility is confined to the coating material and the metal serves merely as a core. Also in the prior art of which I am aware, cores for gaskets have been formed by punching a plurality of closely spaced holes in the sheet. The die means employed forms a small flange around each hole, which flange projects only from one face of the sheet. This process, which is slow and expensive, increases the resiliency of the sheet but very slightly, if at all, and its main advantage lies in securing better adherence of the coating material to the core of the gasket.

There are many instances where greater resiliency in sheet metal is desirable, and the present invention provides a method of securing this greater resiliency. If, for example, a sheet of stock is required to have an effective-thickness of, say, .036 of an inch, I start with a sheet of metal that is much thinner than .036 of an inchsay, a sheet of metal having between .004 and .012 of an inch thickness. To this sheet of metal, I apply pressure to the obverse face of the sheet at a plurality of points arranged in uniformly spaced apart rows, each of which rows contains a plurality of points similarly uniformly spaced apart therein. Simultaneously I apply pressure to the reverse face of the sheet at a plurality of points arranged in uniformly spaced apart rows and with each row containing a plurality of points uniformly spaced apart therein. Furthermore, I apply pressure to the reverse face of the sheet in such manner that the rows of pressure points are located midway between the rows of pressure points on the obverse face of the sheet, and the individual points in the rows are similarly located midway between the points in the rows on the obverse face.

As a result of this application of pressure, the sheet of metal is distorted simultaneously in two directions, formingtherein a plurality of projections rising out of the obverse face of the sheet and a similar plurality of projections depending below the reverse face of the sheet. The projections on the obverse face are uniformly spaced apart in rows which are uniformly spaced apart, and the projections depending from the reverse face are in similar rows and located midway between the rows and projections on the obverse face. The projections so formed are hollow so that in addition to the projections rising out of the obverse face of the sheet there are a plurality of sockets or pockets depressed into that face, these sockets being the interiors of the projections depending from the reverse face of the sheet. Similarly sockets are depressed into the reverse face of the sheet, these sockets being the interiors of the projections on the obverse face thereof. When treated in this manner, a sheet of stock of .004 of an inch gauge thickness is increased to an effective thickness in the range of .036 of an inch.

This simultaneous distortion of the sheet in two directions stretches the metal in the projections thus formed and in most instances the pressure applied will be in excess of the strength of the metal, with the result that the metal is ruptured or torn at or near the apeXes of the projections. This working of the metal also hardens it, with the result that the resiliency of the sheet is greatly enhanced. In one instance, a sheet of .0057 gauge quarter hard steel shim stock, when subjected to pressures of 5,000 pounds per square inch, was compressed to a thickness of .0056 of an inch, and upon removal of the pressure therefrom showed a recovery to .0057 of an inch. The same stock, after treatment as above, to increase its effective thickness to .0296 of an inch, when subjected to pressures of 5,000 pounds per square inch, was compressed to a thickness of .0231 of an inch, and upon removal of the pressure from the sheet recovered to a final thickness of .0237 of an inch.

Material treated in the foregoing manner may be put to a number of uses; for example, it may be coated with a suitable coating material to form a gasket having a metal core and coating material disposed on both faces of that core. The sockets depressed into the faces of the material and the projections rising out of those faces, together form a plurality of pockets which may be filled with the coating material. The coating material is thus secured to the core and even though the coating material may plasticize under the heat to which the gasket is subjected, the material will be firmly held on the core by it's intrusion into the pockets therein and the efiiciency of the gasket therefore is not impaired by the increase in plasticity of the coating material.

Referring now to the drawings, particularly Figs. 1, 2 and 3, it will be seen that on the obverse face of the sheet of material are a plurality of projections rising out of the face and a plurality of sockets 11 depressed therein. As will be seen in Fig. 2 the projections 10 appear on the reverse face of the sheet as sockets depressed therein, and the sockets 11 appear as projections rising out of the reverse face.

As will beseen in Figs. 1 and 2 the projections rising out of both faces of the material are ruptured at or near the apexes of the projections, and the perforations thus formed in the sheet are irregular in shape and are not formed by punching, there being no slugs of metal removed from the sheet but rather the portions 12 torn out of the projections remain partially attached to those projections and extend into the perforations thus formed in the metal. It will be noted that the perforationsthus formed are not uniform in size and are of varying shapes.

The metal 14 in the row of projections 10 disposed between the adjacent projections is bounded on two sides by upwardly turned portions 15 that merge into the projections 10, and this area of metal 14 is bounded on the other two sides disposed at right angles to the portions 15 by downwardly turned portions 16 that merge into the projections 11 in the reverse face of the sheet.

The projections 10 and 11 produced in the two faces of the sheet of stock by the simultaneous application of pressures to both faces at spaced apart points thereon are formed by stretching the metal in the sheet in the direction of the force, that is at right angles to the faces of the sheet. This stretching of the metal reducesits thickness and the metal punctures at or near the a'p'exes of the projections. It will be noted that the perforations thus formed are irregular in size and shape.

The metal may be treated according to the foregoing method in a number of ways. In Figs. 4, 5 and 6 I have shown diagrammatically one arrangement for producing this effect. Dies 20 and 21 contain rows of pyramidal projections 22 and 23 respectively, which projections are uniformly spaced apart in the rows, and the die 21 is positioned so that the apexes of the projections 23 are located midway between the apexes of the projections 22 in the die 20, both as to rows and as to individual projections in the rows. The adjacent faces of adjacent projections 22 in the die shown in Figs. 4 and 5, are positioned with an included angle of 60 therebetween, as indicated.

The projections 22 terminate in points at their apexes. The projections 23 on die 21 are of similar design. As shown, the dies 20 and 21 are planar, that is, the apexes of the projections 22 and 23 thereof terminate in a plane common to each die; and when the dies are moved together, a sheet of stock 24 disposed therebetween is formed to the configuration shown in Figs. 1 to 3. If desired, the dies may be made as cylinders from the periphery of which the projections 22 and 23 project radially, the dies then being rotated around parallel axes to draw the stock 24 therebetween and to form it in the desired manner.

It will be noted in Fig. 1 that the sockets 11 pressed into the stock by engagement of the die 20 with the obverse face of the sheet show rectangular form corresponding to the pyramidal projections 22 on the die. It will also be noted that the projections 10, pressed out of the obverse face of the sheet by the engagement of die 21 with the reverse face thereof, are more irregular in shape and tend toward rounded shape at the apex of the projections. Fig. 2 shows a similar condition on the reverse face of the sheet.

In Figs. 10 to 12, inclusive, I have shown a modified form of die through the use of which the sheet metal takes on the form shown in-Fig's. 7, 8 and 9, after application of the process of the present invention thereto. The upper die 50 and the lower die 51 each have a series of uniformly spaced pyramidal projections 52 and 53, respectively, which projections are spaced apart the same as in the dies 20 and 21, in one instance being spaced .047 inch apart in the rows, with the rows spaced the same distance apart.

In the dies 50 and 51, the angle included between the adjacent faces of adjacent projections is 45 rather than the 60 included angle of dies 20 and 21. As a result of this, projections 52 and 53 project farther out of the base of the dies than formerly.

As will be seen best in Fig. 12, the apexes of the pyramidal projections 52 and 53 are flattened to form square ends on the projections, which ends in one instance measure .010 inch in each direction. As a result of this die configuration, when the sheet of metal 54 is pressed between the dies, the projections 60 upstanding out of the obverse face of the sheet, as shown in Fig. 7, are torn at their respective apexes to form rectangular performations 61 therein. It will be noted that these per forations are irregular and that portions 62 of the metal therein project into the perforations as before.

The engagement of the die 50 with the obverse face of the sheet depresses sockets 63 into the sheet as before. It will be noted that the sockets assume a substantially rectangular shape as defined by the configuration of the dies.

The metal 64 intervening between adjacent projections 60 is bounded at its two sides by upturned portions 65 which blendinto the projections 60, and at its other two sides the metal 64 is bent downwardly, as shown at 66, merging into the sockets 63 depressed in the obverse face. Die marks 67 are visible in at least some of the upstanding projections 60.

On the reverse side of the sheet as shown in Fig. 9, the sockets 63 appear as projections upstanding out of the reverse face and are pierced by perforations 68 into which unsevered portions 69 project. The projections 60 on the obverse face of the sheet appear as sockets in the reverse face thereof, which sockets, like the sockets 63 in the obverse face, assume the square configuration of the dies. Die marks 67 are also clearly visible on the reverse side of the sheet.

The metal 70 disposed between adjacent projections 63 is bounded at two edges by portions 71 which are upturned and merge into the projections 63, and bounded at the other two edges by portions 72 which bow downwardly, merging into the sockets 60 in the reverse face.

The irregular shape of the perforations in the projections 63 in the reverse face is clearly shown at 73 in Fig. 8, and that of perforations in the projections 60 on the obverse face of the sheet is clearly shown at 74.

It will be noted by comparison of Figs. 3 and 8, that the curvature of the portions 71 and 72 of the metal 69 intervening between the adjacent projections on the reverse face is at a much sharper angle than are the portions 15 and 16 of the metal 14 in the embodiment shown in Fig. 3. The same is true of the portions on the obverse face of the sheet, although not so clearly visible in Figs. 3 and 8 because of the light reflections contained therein.

The dies 20 and 21, and 50 and 51, may be made of sufiicient size to cover the entire area needed in the sheet for the purpose for which it is intended; however, the power required to operate on the entire area of such a sheet at one time is very great and more than can reasonably be expected to be available. Therefore, I prefer to make the dies of sufficient length to span the web of metal transversely and of convenient width longitudinally of that web to fit into the power that is available. In one instance, where a web of eight inches in width was to be treated, the dies were two inches wide longitudinally of the web, and the web was indexed forwardly exactly two inches between successive operations of the dies. As a result, the web of metal was treated in accordance with the teachings of the present invention and subsequently cut into lengths suitable for the purposes intended.

It is also contemplated that the dies may be in the form of cylinders from the surface of which pyramidal projections extend radially. Metal passed between such rolls will be shaped to the form shown in the drawings.

It will be noted that the pockets formed in each face of the metal and appearing therein as the interiors of hollow projections on the opposite face are augmented by projections out of the face of the metal into which the pocket extends. As a result, a sheet of metal treated in accordance with the teachings of the present invention contains a plurality of relatively deep pockets into which a coating material can be placed and securely held.

As will be readily apparent, initial application of pressures at right angles to the faces of the sheet will deform the jagged edges of the metal adjacent the apexes of the projections, this deformation continuing until the resistance of the adjacent metal equals or exceeds the pressures applied to the sheet. Further application of pressure deforms the remaining metal which, because of the treatment given it, has increased resiliency, with the result that when the pressure is removed the sheet returns towards its original condition, the deformations at the apexes of the projections remaining and thereby decreasing somewhat the effective thickness of the sheet.

In the embodiments of the invention shown by way of example, pressure is applied to both faces of the sheet at a plurality of points which are spaced apart uniformly throughout the sheet, and as a result the projections and sockets formed in the sheet are uniformly spaced. While this uniform spacing is advantageous in many instances, it is not essential to the teachings of the invention. It is contemplated that there may be instances where it Will be advantageous to have non-uniform spacing of the projections and sockets, that is close spacing in a part of the sheet and a wider spacing in other parts thereof.

.6 With suitable formation of the die means by which the sheet is operated upon, any desired degree of uniformity of spacing can be achieved.

From the foregoing, it will be apparent that through the teachings of the present invention a sheet of relatively thin metal can be increased in effective thickness with an appreciable increase in the resiliency of the sheet over that of the stock from which it is made. While the sheet of the present invention is of particular advantage in the formation of gaskets and the like, it is contemplated that the material so formed may be put to other uses.

While I have chosen to illustrate my invention by showing and describing a preferred embodiment of it, I have done so by way of example only, as there are many modifications and adaptations which can be made by one skilled in the art within the teachings of the invention.

Having thus complied with the statutes and shown and described a preferred embodiment of my invention, what I consider new and desire to have protected by Letters Patent is pointed out in the appended claims.

What I claim is:

1. A sheet stock made of a metal selected from the group consisting of copper, brass and steel, and of approximately .006" thickness formed into a gasket stock having an effective thickness of approximately .030 and consisting of a plurality of generally pyramidal sockets indented into each face of the stock, each socket forming a projection rising out of the other face of the stock, the outer face of each projection being somewhat rounded and blended into the inner surfaces of sockets indented into the face of the stock out of which the projections rise whereby the increase of effective thickness and resiliency of the stock are achieved; said sockets being uniformly spaced apart in uniformly spaced apart rows which the sockets and rows on the obverse face of the stock located midway between the sockets and rows on the reverse face thereof, said rows of sockets and sockets in the rows being spaced approximately .047" apart, whereby said sockets and projections aid in bonding facing materials onto the stock.

2. A sheet stock as specified in claim 1, in which each projection is ruptured and has an irregularly shaped opening adjacent its apex.

3. A sheet stock made of a metal selected from the group consisting of copper, brass and steel of thickness in the range of .004" to .012" formed into a gasket stock having an effective thickness in the range of .0296 to .036" and ocnsisting of a plurality of generally pyramidal sockets indented into each face of the stock, each socket forming a projection rising out of the other face of the stock, the outer face of each projection being somewhat rounded and blended into the inner surfaces of sockets indented into the face of the stock out of which the projections rise whereby the increase of effective thickness and resiliency of the stock are achieved, said sockets being uniformly spaced apart in uniformly spaced apart rows with the sockets and rows on the obverse face of the stock located midway between the sockets and rows on the reverse face thereof, said rows of sockets and sockets therein being spaced approximately .047" apart, said sockets and projections together defining pockets in each face of the stock whereby a facing material filling the pockets and secured to the core by bonding is fixed against displacement with respect to the core.

4. A sheet stock as specified in claim 3, in which said pockets are separated by portions of the stock disposed between adjacent projections and sockets, which portions are bowed upwardly on two edges and blended into adjacent projections and are bowed downwardly on their other two edges and blended into adjacent sockets.

5. A sheet stock as specified in claim 4, in which each projection is ruptured and has an irregularly shaped opening adjacent its apex.

(References on following page) 

1. A SHEET STOCK MADE OF A METAL SELECTED FROM THE GROUP CONSISTING OF COPPER, BRASS AND STEEL, AND OF APPROXIMATELY .006" THICKNESS FORMED INTO A GASKET STOCK HAVING AN EFFECTIVE THICKNESS OF APPROXIMATELY .030 AND CONSISTING OF A PLURALITY OF GENERALLY PYRAMIDAL SOCKETS ING A PROJECTION RISING OUT OF THE OTHER FACE OF THE STOCK, THE OUTER FACE OF EACH PROJECTION BEING SOMEWHAT ROUNDED AND BLENDED INTO THE INNER SURFACES OF SOCKETS INDENTED INTO THE FACE OF THE STOCK OUT OF WHICH THE PROJECTIONS RISE WHEREBY THE INCREASE OF EFFECTIVE THICKNESS AND RESILIENCY OF THE STOCK ARE ACHIEVED; SAID SOCKETS BEING UNIFORMLY SPACED APART IN UNIFORMLY SPACED APART ROWS WHICH THE SOCKETS AND ROWS ON THE OBVERSE FACE OF THE STOCK LOCATED MIDWAY BETWEEN THE SOCKETS AND ROWS ON THE REVERSE FACE THEREOF, SAID ROWS OF SOCKETS AND SOCKETS IN THE ROWS BEING SPACED APPROXIMATELY .047" APART, WHEREBY SAID SOCKETS AND PROJECTIONS AID IN BONDING FACING MATERIALS ONTO THE STOCK. 